<?php
	# 扩展分页类，实现用 ajax 分页

    class MY_Pagination extends CI_Pagination {

        /**
         * Base URL
         *
         * The page that we're linking to
         *
         * @var	string
         */
        protected $base_url	= '';

        /**
         * Prefix
         *
         * @var	string
         */
        protected $prefix = '';

        /**
         * Suffix
         *
         * @var	string
         */
        protected $suffix = '';

        /**
         * Total number of items
         *
         * @var	int
         */
        protected $total_rows = 0;

        /**
         * Number of links to show
         *
         * Relates to "digit" type links shown before/after
         * the currently viewed page.
         *
         * @var	int
         */
        protected $num_links = 2;

        /**
         * Items per page
         *
         * @var	int
         */
        public $per_page = 10;

        /**
         * Current page
         *
         * @var	int
         */
        public $cur_page = 0;

        /**
         * Use page numbers flag
         *
         * Whether to use actual page numbers instead of an offset
         *
         * @var	bool
         */
        protected $use_page_numbers = FALSE;

        /**
         * First link
         *
         * @var	string
         */
        protected $first_link = '&lsaquo; First';

        /**
         * Next link
         *
         * @var	string
         */
        protected $next_link = '&gt;';

        /**
         * Previous link
         *
         * @var	string
         */
        protected $prev_link = '&lt;';

        /**
         * Last link
         *
         * @var	string
         */
        protected $last_link = 'Last &rsaquo;';

        /**
         * URI Segment
         *
         * @var	int
         */
        protected $uri_segment = 0;

        /**
         * Full tag open
         *
         * @var	string
         */
        protected $full_tag_open = '';

        /**
         * Full tag close
         *
         * @var	string
         */
        protected $full_tag_close = '';

        /**
         * First tag open
         *
         * @var	string
         */
        protected $first_tag_open = '';

        /**
         * First tag close
         *
         * @var	string
         */
        protected $first_tag_close = '';

        /**
         * Last tag open
         *
         * @var	string
         */
        protected $last_tag_open = '';

        /**
         * Last tag close
         *
         * @var	string
         */
        protected $last_tag_close = '';

        /**
         * First URL
         *
         * An alternative URL for the first page
         *
         * @var	string
         */
        protected $first_url = '';

        /**
         * Current tag open
         *
         * @var	string
         */
        protected $cur_tag_open = '<strong>';

        /**
         * Current tag close
         *
         * @var	string
         */
        protected $cur_tag_close = '</strong>';

        /**
         * Next tag open
         *
         * @var	string
         */
        protected $next_tag_open = '';

        /**
         * Next tag close
         *
         * @var	string
         */
        protected $next_tag_close = '';

        /**
         * Previous tag open
         *
         * @var	string
         */
        protected $prev_tag_open = '';

        /**
         * Previous tag close
         *
         * @var	string
         */
        protected $prev_tag_close = '';

        /**
         * Number tag open
         *
         * @var	string
         */
        protected $num_tag_open = '';

        /**
         * Number tag close
         *
         * @var	string
         */
        protected $num_tag_close = '';

        /**
         * Page query string flag
         *
         * @var	bool
         */
        protected $page_query_string = FALSE;

        /**
         * Query string segment
         *
         * @var	string
         */
        protected $query_string_segment = 'per_page';

        /**
         * Display pages flag
         *
         * @var	bool
         */
        protected $display_pages = TRUE;

        /**
         * Attributes
         *
         * @var	string
         */
        protected $_attributes = '';

        /**
         * Link types
         *
         * "rel" attribute
         *
         * @see	CI_Pagination::_attr_rel()
         * @var	array
         */
        protected $_link_types = array();

        /**
         * Reuse query string flag
         *
         * @var	bool
         */
        protected $reuse_query_string = FALSE;

        /**
         * Use global URL suffix flag
         *
         * @var	bool
         */
        protected $use_global_url_suffix = FALSE;

        /**
         * Data page attribute
         *
         * @var	string
         */
        protected $data_page_attr = 'data-ci-pagination-page';

        /**
         * CI Singleton
         *
         * @var	object
         */
        protected $CI;

        // --------------------------------------------------------------------

        /**
         * Constructor
         *
         * @param	array	$params	Initialization parameters
         * @return	void
         */
        public function __construct($params = array())
        {
            $this->CI =& get_instance();
            $this->CI->load->language('pagination');
            foreach (array('first_link', 'next_link', 'prev_link', 'last_link') as $key)
            {
                if (($val = $this->CI->lang->line('pagination_'.$key)) !== FALSE)
                {
                    $this->$key = $val;
                }
            }

            $this->initialize($params);
            log_message('info', 'Pagination Class Initialized');
        }

        // --------------------------------------------------------------------

        /**
         * Initialize Preferences
         *
         * @param	array	$params	Initialization parameters
         * @return	CI_Pagination
         */
        public function initialize(array $params = array())
        {
            isset($params['attributes']) OR $params['attributes'] = array();
            if (is_array($params['attributes']))
            {
                $this->_parse_attributes($params['attributes']);
                unset($params['attributes']);
            }

            // Deprecated legacy support for the anchor_class option
            // Should be removed in CI 3.1+
            if (isset($params['anchor_class']))
            {
                empty($params['anchor_class']) OR $attributes['class'] = $params['anchor_class'];
                unset($params['anchor_class']);
            }

            foreach ($params as $key => $val)
            {
                if (property_exists($this, $key))
                {
                    $this->$key = $val;
                }
            }

            if ($this->CI->config->item('enable_query_strings') === TRUE)
            {
                $this->page_query_string = TRUE;
            }
            if ($this->use_global_url_suffix === TRUE)
            {
                $this->suffix = $this->CI->config->item('url_suffix');
            }

            return $this;
        }

        // --------------------------------------------------------------------

        /**
         * Generate the pagination links
         *
         * @return	string
         */
        public function create_links()
        {

            // If our item count or per-page total is zero there is no need to continue.
            // Note: DO NOT change the operator to === here!
            if ($this->total_rows == 0 OR $this->per_page == 0)
            {
                return '';
            }

            // Calculate the total number of pages
            $num_pages = (int) ceil($this->total_rows / $this->per_page);

            // Is there only one page? Hm... nothing more to do here then.
            if ($num_pages === 1)
            {
                return '';
            }

            // Check the user defined number of links.
            $this->num_links = (int) $this->num_links;

            if ($this->num_links < 0)
            {
                show_error('Your number of links must be a non-negative number.');
            }

            // Keep any existing query string items.
            // Note: Has nothing to do with any other query string option.
            if ($this->reuse_query_string === TRUE)
            {
                $get = $this->CI->input->get();

                // Unset the controll, method, old-school routing options
                unset($get['c'], $get['m'], $get[$this->query_string_segment]);
            }
            else
            {
                $get = array();
            }

            // Put together our base and first URLs.
            // Note: DO NOT append to the properties as that would break successive calls
            $base_url = trim($this->base_url);

            $first_url = $this->first_url;

            $query_string = '';
            $query_string_sep = (strpos($base_url, '?') === FALSE) ? '?' : '&amp;';

            // Are we using query strings?
            if ($this->page_query_string === TRUE)
            {
                // If a custom first_url hasn't been specified, we'll create one from
                // the base_url, but without the page item.
                if ($first_url === '')
                {
                    $first_url = $base_url;

                    // If we saved any GET items earlier, make sure they're appended.
                    if ( ! empty($get))
                    {
                        $first_url .= $query_string_sep.http_build_query($get);
                    }
                }

                // Add the page segment to the end of the query string, where the
                // page number will be appended.
                $base_url .= $query_string_sep.http_build_query(array_merge($get, array($this->query_string_segment => '')));
            }
            else
            {
                // Standard segment mode.
                // Generate our saved query string to append later after the page number.
                if ( ! empty($get))
                {
                    $query_string = $query_string_sep.http_build_query($get);
                    $this->suffix .= $query_string;
                }

                // Does the base_url have the query string in it?
                // If we're supposed to save it, remove it so we can append it later.
                if ($this->reuse_query_string === TRUE && ($base_query_pos = strpos($base_url, '?')) !== FALSE)
                {
                    $base_url = substr($base_url, 0, $base_query_pos);
                }
                //第一次给   $first_url 赋值
                if ($first_url === '')
                {
                    $first_url = $base_url.$query_string;
                }

                $base_url = rtrim($base_url, '/').'/';
            }

            // Determine the current page number.
            $base_page = ($this->use_page_numbers) ? 1 : 0;

            // Are we using query strings?
            if ($this->page_query_string === TRUE)
            {
                $this->cur_page = $this->CI->input->get($this->query_string_segment);
            }
            elseif (empty($this->cur_page))
            {
                // Default to the last segment number if one hasn't been defined.
                if ($this->uri_segment === 0)
                {
                    $this->uri_segment = count($this->CI->uri->segment_array());
                }

                $this->cur_page = $this->CI->uri->segment($this->uri_segment);

                // Remove any specified prefix/suffix from the segment.
                if ($this->prefix !== '' OR $this->suffix !== '')
                {
                    $this->cur_page = str_replace(array($this->prefix, $this->suffix), '', $this->cur_page);
                }
            }
            else
            {
                $this->cur_page = (string) $this->cur_page;
            }

            // If something isn't quite right, back to the default base page.
            if ( ! ctype_digit($this->cur_page) OR ($this->use_page_numbers && (int) $this->cur_page === 0))
            {
                $this->cur_page = $base_page;
            }
            else
            {
                // Make sure we're using integers for comparisons later.
                $this->cur_page = (int) $this->cur_page;
            }

            // Is the page number beyond the result range?
            // If so, we show the last page.
            if ($this->use_page_numbers)
            {
                if ($this->cur_page > $num_pages)
                {
                    $this->cur_page = $num_pages;
                }
            }
            elseif ($this->cur_page > $this->total_rows)
            {
                $this->cur_page = ($num_pages - 1) * $this->per_page;
            }

            $uri_page_number = $this->cur_page;

            // If we're using offset instead of page numbers, convert it
            // to a page number, so we can generate the surrounding number links.
            if ( ! $this->use_page_numbers)
            {
                $this->cur_page = (int) floor(($this->cur_page/$this->per_page) + 1);
            }

            // Calculate the start and end numbers. These determine
            // which number to start and end the digit links with.
            $start	= (($this->cur_page - $this->num_links) > 0) ? $this->cur_page - ($this->num_links - 1) : 1;
            $end	= (($this->cur_page + $this->num_links) < $num_pages) ? $this->cur_page + $this->num_links : $num_pages;


            //刘现彬-一下两行为添加-设置第一页伪静态url
            if($this->CI->config->item('url_suffix')!=='')
            {
                $this->suffix = $this->CI->config->item('url_suffix');
                $this->first_url= rtrim((($this->first_url == '') ? $this->base_url : $this->first_url), '/').$this->suffix;
                if(!strstr($first_url,$this->CI->config->item('url_suffix')))
                {
                    $first_url.=$this->CI->config->item('url_suffix');
                }
            }


            // And here we go...
            $output = '';



            // Render the "First" link.
            if ($this->first_link !== FALSE && $this->cur_page > ($this->num_links + 1 + ! $this->num_links))
            {
                // Take the general parameters, and squeeze this pagination-page attr in for JS frameworks.
                $attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, 1);

                $output .= $this->first_tag_open.'<a href="'.$first_url.'"'.$attributes.$this->_attr_rel('start').'>'
                    .$this->first_link.'</a>'.$this->first_tag_close;
                // print_r($first_url);
            }

            // Render the "Previous" link.
            if ($this->prev_link !== FALSE && $this->cur_page !== 1)
            {
                $i = ($this->use_page_numbers) ? $uri_page_number - 1 : $uri_page_number - $this->per_page;

                $attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, ($this->cur_page - 1));

                if ($i === $base_page)
                {
                    // First page
                    $output .= $this->prev_tag_open.'<a href="'.$first_url.'"'.$attributes.$this->_attr_rel('prev').'>'
                        .$this->prev_link.'</a>'.$this->prev_tag_close;
                }
                else
                {
                    $append = $this->prefix.$i;//.$this->suffix;

                    $output .= $this->prev_tag_open.'<a href="'.$base_url.$append.'"'.$attributes.$this->_attr_rel('prev').'>'
                        .$this->prev_link.'</a>'.$this->prev_tag_close;
                }

            }

            // Render the pages
            if ($this->display_pages !== FALSE)
            {
                // Write the digit links
                for ($loop = $start - 1; $loop <= $end; $loop++)
                {
                    $i = ($this->use_page_numbers) ? $loop : ($loop * $this->per_page) - $this->per_page;

                    $attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, $loop);

                    if ($i >= $base_page)
                    {
                        if ($this->cur_page === $loop)
                        {
                            // Current page
                            $output .= $this->cur_tag_open.$loop.$this->cur_tag_close;
                        }
                        elseif ($i === $base_page)
                        {
                            // First page
                            $output .= $this->num_tag_open.'<a href="'.$first_url.'"'.$attributes.$this->_attr_rel('start').'>'
                                .$loop.'</a>'.$this->num_tag_close;
                        }
                        else
                        {
                            $append = $this->prefix.$i.$this->suffix;
                            $base_url=str_replace(".html","",$base_url);//刘现彬-替换.html为""
                            $output .= $this->num_tag_open.'<a href="'.$base_url.$append.'"'.$attributes.'>'
                                .$loop.'</a>'.$this->num_tag_close;
                        }
                    }
                }
            }

            // Render the "next" link
            if ($this->next_link !== FALSE && $this->cur_page < $num_pages)
            {
                $i = ($this->use_page_numbers) ? $this->cur_page + 1 : $this->cur_page * $this->per_page;

                $attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, $this->cur_page + 1);

                $output .= $this->next_tag_open.'<a href="'.$base_url.$this->prefix.$i.$this->suffix.'"'.$attributes
                    .$this->_attr_rel('next').'>'.$this->next_link.'</a>'.$this->next_tag_close;
            }

            // Render the "Last" link
            if ($this->last_link !== FALSE && ($this->cur_page + $this->num_links + ! $this->num_links) < $num_pages)
            {
                $i = ($this->use_page_numbers) ? $num_pages : ($num_pages * $this->per_page) - $this->per_page;

                $attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, $num_pages);

                $output .= $this->last_tag_open.'<a href="'.$base_url.$this->prefix.$i.$this->suffix.'"'.$attributes.'>'
                    .$this->last_link.'</a>'.$this->last_tag_close;
            }

            // Kill double slashes. Note: Sometimes we can end up with a double slash
            // in the penultimate link so we'll kill all double slashes.
            $output = preg_replace('#([^:"])//+#', '\\1/', $output);
            //$CI
            $url_suffix=$this->CI->config->item('url_suffix');
            //echo("---".$output."---");
            if(strpos($output,'?') !== false)
            {
                $output=str_replace($url_suffix,'',$output);
                $output=str_replace("?",$url_suffix."?",$output);
            }

            //print_r($output);die;
            // Add the wrapper HTML if exists
            return $this->full_tag_open.$output.$this->full_tag_close;
        }

        // --------------------------------------------------------------------

        /**
         * Parse attributes
         *
         * @param	array	$attributes
         * @return	void
         */
        protected function _parse_attributes($attributes)
        {
            isset($attributes['rel']) OR $attributes['rel'] = TRUE;
            $this->_link_types = ($attributes['rel'])
                ? array('start' => 'start', 'prev' => 'prev', 'next' => 'next')
                : array();
            unset($attributes['rel']);

            $this->_attributes = '';
            foreach ($attributes as $key => $value)
            {
                $this->_attributes .= ' '.$key.'="'.$value.'"';
            }
        }

        // --------------------------------------------------------------------

        /**
         * Add "rel" attribute
         *
         * @link	http://www.w3.org/TR/html5/links.html#linkTypes
         * @param	string	$type
         * @return	string
         */
        protected function _attr_rel($type)
        {
            if (isset($this->_link_types[$type]))
            {
                unset($this->_link_types[$type]);
                return ' rel="'.$type.'"';
            }

            return '';
        }

    }
